Introduction: Cancer prevention and treatment are critical today. The best efforts are being made to combat this disease through multidisciplinary scientific investigations. Background and purpose: The current study sought to assess the antitumor effects of volatile oils extracted from the leaves of Citrus aurantium and Citrus sinensis, as well as the antioxidant enzyme levels. Materials and methods: The volatile oils isolated from the leaves of Citrus aurantium and Citrus sinensis at 25mg/kg and 50mg/kg in an emusion form using acacia gum were tested for antitumor activity in DAL (Dalton's Ascites Lymphoma) bearing swiss albino mice. The tumor cell count, body weight, percentage of increased life span, liver antioxidant enzymes, and histopathological changes in the liver and kidney were studied to interpret the results. As a positive control, 5 Flurouracil at 20mg/kg was used as standard. Results: The current study demonstrates the potency of volatile oil from Citrus aurantium (VOCA) and Citrus sinensis (VOCS) in vivo antitumor activity without significant changes in the toxicity parameters evaluated. It was discovered that VOCA and VOCS exerted a dose-dependent decrease in cell viability and increased protection against experimental animals from the deleterious effect of DAL-induced tumor in mice.